Abstract
Current efforts in sorghum breeding programs are exploiting genotyping-by-sequencing (GBS) data to provide full-genome scans for desired traits. The aim of this study was to utilize GBS approach for the identification of genomic regions associated with stress response in sorghum (Sorghum bicolor L. Monech) accessions. DNA samples of twenty sorghum accessions, having different response to drought, were used to prepare GBS libraries for sequencing. SNPs were called using the TASSELGBS pipeline and the tags that present at least 10 times in the dataset were considered and aligned to the reference genome of Sorghum bicolor. The identified SNPs were all compared with the published sorghum transcript related to stress response gene activity. Overall; 94.40% tags were aligned and 69,736 putative SNPs positions were identified. Blast search revealed homology to annotated heat and drought–tolerance associated genes which code for ATPases, Peroxidase, Hydrophobic protein LTI6A, Aquaporin SIP2-1, Aconitate hydratase and phosphatidylinositol-4-phosphate-5-kinase. The phylogeny of the 20 accessions was constructed using the generated SNPs data. Phylogenetic analysis data showed that the phenotypically tolerant line (El9) makes a separate cluster and the same for the accessions HSD8653 and HSD5612 near to the cluster that includes most accessions with known post-flowering drought tolerance (HSD7410, HDS10033, HSD8552, GESHEISH and HSD8849). Post-flowering drought sensitive accessions (Tabat, Wadahmed, HSD6468 and HSD6478) formed a separate cluster while the sensitive accession HSD9959 and the tolerant accessions HSD8511 and HSD9566 were distributed between the two clusters. Thus, cluster analysis confirmed the variation among accessions in post-flowering drought tolerance. With further validation, these markers may be used for marker assisted selection for breeding new sorghum genotypes with stress adaptation.
Highlights
Sorghum is the dietary staple food for about 500 million people over 30 countries and is especially important in semi-arid regions of Africa, along with pearl millet and cassava [1]
Post-flowering drought sensitive accessions (Tabat, Wadahmed, HSD6468 and HSD6478) formed a separate cluster while the sensitive accession HSD9959 and the tolerant accessions HSD8511 and HSD9566 were distributed between the two clusters
Drought response in sorghum has been classified into two distinct stages; pre-flowering drought response that occurs prior to anthesis and post-flowering drought response that is observed when water limitation occurs during the grain-filling stage
Summary
Sorghum is the dietary staple food for about 500 million people over 30 countries and is especially important in semi-arid regions of Africa, along with pearl millet and cassava [1]. It is believed that sorghum yields and/or further resistance to biotic and abiotic factors could be improved upon using suitable improved varieties, and preferably developed from environmentally suited local landraces and/or wild/weedy varieties [2]. Important abiotic stresses in sorghum are broadly defined into three categories: water, temperature, and nutrition. Drought response in sorghum has been classified into two distinct stages; pre-flowering drought response that occurs prior to anthesis and post-flowering drought response that is observed when water limitation occurs during the grain-filling stage. Post-flowering drought stress tolerance is indicated when plants remain green and fill grain normally [4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
